Escapement mechanism



p 9, 1952 H. J. GRAHAM ET AL 2,611,911

ESCAPEMENT MECHANISM Filed Dec. 15, 1949 Patented Sept. 30, 1952 ESCAPEMENT MECHANISM Harold J. Graham, Highland Park, and Paul F. Powder, Detroit, Mich.,- assignors to Graham Manufacturing Corporation, Detroit, Mich., a

corporation of Michigan Application December 15, 1949, Serial No. 133,162

This invention relates to escapement mechanism and more particularly to the type of escapement used to deliver or transfer studs, screws, pins or similarly shaped machine elements from a storage magazine.

Objects of this invention are to provide an escapement mechanism which will successively deliver studs or other pieces from a magazine as they are required by a welder or other apparatus, which is simple in construction, which is rapid and automatic in operation, which is not subject to jamming, which is adaptable to mass production techniques, which is operable by compressed air or other working fluid, which is economical to manufacture and which improves the art generally.

In a broad aspect the invention contemplates an escapement for feeding one stud or other piece at a time from a magazine or other storage place, which escapement comprises a body having a passageway therein acting as a, path along which the studs proceed in stacked relationship from the magazine. The passageway is normally blocked by a centrally positioned finger so that the stack of studs is restrained from further movement. Two flanking fingers are disposed along the passageway on either side of the central finger at respective distances greater than the longitudinal length of one of the studs.

Means are provided for moving the fingers sothat the stack is restrained by one of the flanking fingers as the bottom-most stud is transferred from the central finger to the other flanking finger, the subsequent return of the fingers to their normal positions releasing the bottom-most stud so that it is delivered to the welding gun or other apparatus.

In another aspect the body is provided with three cylindrical cavities whose respective axes intersect the axis of the passageway for the studs. Each cavity has reciprocatingly arranged therein a piston or plunger carrying a finger. The centrally arranged plunger is biased so that its finger normally blocks the passageway thereby to restrain the studs from continuing through such passageway. The outer cavities are positioned on either side of the central cavity so that the flanking fingers are disposed along the passageway on either side of the central finger at respective distances greater than the longitudinal length of an individual stud. The fingers are moved by a working fluid which may be either hydraulic or pneumatic, introduced behind the plungers so that the corresponding fingers are moved to transfer the studs.

3 Claims. (C1. 10-162) connect the respective outer cavities with: the

central cavity; These latter passages are positioned so that air is introduced from the central cavity to the outer cavities whereby the outer fingers are moved against the forces exerted by correlated springs after the transfer of thecentral plunger from the passageway blocking-position. The movement of one of the flanking fingers brings the end thereof into contact with the next-to-the-bottom stud thereby restraining such stud and the studs stacked thereabove. The other flanking finger is moved to block the passageway to restrainthe bottom-most stud released previously by the retraction of the central finger. Subsequent disconnecting of the air supply permits the springs to return the correlated fingers to their normal positions thereby dropping the stack until it is againrestrained by the central finger and simultaneously releasing the bottom-most stud held by the second flanking finger.

These and further objects, aspects and advantages of the invention will be apparent from the following detailed description and by reference to the accompanying drawings wherein.

Fig. 1 is an end view of the escapement;

Fig. 2 is a sectional view on the line 2-2 of Fig. 1 showing the fingers in their normal'positions; and

Fig. 3 is a sectional view on the line 2'2- of Fig. 1 showing the fingers in their transferred positions.

Referring to the drawings, the escapement 26 comprises a'body 99 wherein is provided an aperture such as the passageway 92 into the top of which the studs S are introduced from a magazine (not shown), for example by a conduit 28. The travel of the studs along the passage 92 is normally blocked, as in Fig. 2, by a tip of a finger M which is reciprocatingly disposed in an aperture having an axis disposed perpendicularly to the axis of the passageway 92. To prevent rapid wear, the tip is preferably of tungsten carbide or other abrasive-resistant material silversoldered to the end of the finger 94.

The finger 94 is biased in its passage-blocking upon a piston 98 attached to one end of-the finger, the finger being pressed into an aperture through the piston. The opposite end of the spring 98 seats in a recess in a head I which is attached to the side of the body 90 by the bolts 99. Arranged on either side of the centrally positioned finger 94 at a distance therefrom greaterilthan tthe overall axial length of an .individualstudS are two flanking fingers I02 and. I03 respectively. With the exception of their axial length these fingers I02 and I03 are similar to each other in construction, each having .a tungsten carbide tip at one end and a skirted piston I04 attached to the lnther end thereof.

Springs I01 are arranged circum-jacent:the fingers I02 and I03 respectively 'betweenthe correlated pistons I04 and the end of the cylinder apertures in the body 90 whereinitherespective pistons I04 are disposed thereby to bias the fingers so that the tips thereof are =-normall-y withdrawn from the passageway 92.

I Tlre:finger:94is.moyedsouteofethepath of the QStudsQS cagainst :the: :restoring- :iorce :exerted by tzheesjr ring:511i a-bymeans of cormiressedzairv or other {working :fluid introduced :througha :conduit d0 0 "(i igmm .zin the zsidezof thezhodywfifl :and thence "mhroughsa passage unto-the cylinderiapertureat -the:fingeriend:of the'pistonfitllir z-Aiter the piston 2&8 hasrmored "atsufiicient ,distance 130"HI1COV81'jD3S- *SE'gES'SSIIChJ-aS rthei ports iI 085511 is introducedbehindrthenpistons, I04 ISO gthat ithercorresponding ifin'gersil0zeand :I 03 ca-re unoved :into .thezpassage- -.way-.92;:as iashowninFigB.

1The: ;conduit..:I-0.6 is connectedito :a supply :of compressedsair :through :a conventional .two way control valve :(not shown) :onezposition, of which :connects thexconduit :to the; air supply, the other avalve -.tposition :hleeding' Ythe; :conduit to atmossphere: Thercnntrol valvermayibe actuated either mechanically, pneumatic ally :or. electrically, depending-months :means inf operation :of the ap- .paratusassociated therewith, ffioraexample, when the escapfimentrisiused .to ffeedstuds a weld- ;ingrgun; the; valve :actuatingmechanismis Earr anged-Jo complete one operating .cycle ofithe walyetduring:each-welding cycle.

As-described heretofore, the studs 8 :are :fed iromethe rmagazinerthrough :the; conduit .28 with random axial orientation. The studs S proceed along the :conduit. 2.8 under the force of I gravity,

:aidedlwif :necessary, by -a stream :of..conrpressed air-:Qnot shown) gthence through the passageway 92 until -,their;forward-progress is blocked by the finger-{94w The-connecting-of the conduit I06 to ifliecconrpresse-d air supply bythe control valve, .asrdescribed above,=retracts the fingers l so that the stack of studs S, is permitted to ztravelrfurther along: the passageway -92. When' the finger .-.94 -has sheen-retracted: sufficiently so "that the piston 98 uncovers the ports I08, the fingers =I-.0-2 :an;d-.-\I 03-rare -.movedinto the passageway .92 so ..that athe- -next-.to-the-bottom :stud isnforced against the passageway wall lay-the finger1-I 02, thereby restraining further movement ofthe stack; the finger J03 simultaneously :blockin the passageway to :stop ;the bottom stud which has rdrqnpedto the position :shown in Fig: 3.

The subsequent venting .of the conduit 106 at .atmosnhere laythe control valve permits the spring-,-!l6 to return thefinger 94 so that it I again blocks the passagewa 9.2.--=The conjoint movement, of .the piston -08 -bleeds the cylinders of the pistons I04 to atmosphere.through-the ports l08 and-.a vent i so that [the springs I0! retract itheqfingers I02 and :I 03. The retraction of finger J02 releases the ,stackwof sstuds so that .it drops i until again restrained by the finger 94. The simultaneous retraction of the finger I03 releases the bottom stud so that it drops into a conduit II 4 leading to the chuck of a welding gun or other apparatus (not shown).

It should he understood that the present dis- -.closureis -for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

Weclaim:

'1. A pneumatically operated escapement for Eeedingronas'tudat .a time from a magazine, comprising-a-body having a passageway therein form- *in a -:path-along which the studs proceed in stackedrelationship from the magazine, said body. alsohaving three cylindrical cavities therein whose respective axes intersect the axis of the passageway, a plunger having a finger associated therewith reciprocatingly disposed in each of the respective :cavities; azspringzbiasin the centrally positionedzfinger so that :it normally blocks the 'passageway'therebyato restrain'the studsJthe two :outer :cavities :ibing :positioned so "that the' two flanking fingers spaced along the :passageway on either side of the central 'finger at respective-distances .2 greater than the longitudinal length of :one :ofthe; studs,:-springs I biasing the' two flanking fingersirespectively"so that theyarenormallyiheld clear of the. passageway, said body. having a plurality: of :sair ipassages therein, the ends of the firs'trof said-passages connecting respectively with :anzairisupply and the central cavity-so that the .centrallzfinger and associated plunger can be 1 movedagainst the "force exerted by the' correlated biasing spring to release the bottom-most=stud, :the other :air passages interconnecting the -re- *spective outer cavities with the central cavity whereby the movement of v the central plunger from the. passageway *blocking position permits air'to flowithroughsuch passages to theou'ter cavitiesrthereby to-move the flanking'plungers so :that the stack is restrained 'by one-of the flank- ;in'gffingers :as the ibottom-most stud is transfer- :red from Ithe central "finger to "the other 'flanking :finger, @the subsequent disconnecting 'of the 'air .-:supply :permitting the springs to return "the gers to their normal -positions releasingthe bottom-moststud.

2. :A .Lfillid operated escapement for feeding aonenstud at 'a timetfroma magazine, comprising :a bodkhavingza passageway-therein forming a path ;along-which the "studs proceed in stacked relationship .from the magazine, said body also having zthree mcylindrical cavities therein whose respective "axes intersect the axis 'of *the passageway, three plungers each having a correlated .finger associated therewith 'reciprocating'ly disposed in :the respective cavities; :a spring biasing :the centrally positionedfinger in a normal posiftion 'blocking thepa'ssageway thereby'to restrain the :stack of studs, the -two :outer cavities being located to position :the 'ltWO flanking tfingers along the passageway .on (either .side of the central finger at-respective distances greater than the longitudinal length of one of the'studs, said'cfl'ank- -ing-fingers being movable frominormalretracted po'sitions whereinthe passageway is unobstructed to blocking positions 'wherein the fingers enter .the r'passageway, fiuidmeansifor retracting the centrally positioned plunger so that the assoiciatedfinger 'releases the stack, said means subsequently moving Ethe-other plungers so that the associated flanking fingers movevinto'their blocking positions wherein :thesta'ckcis restrained by one of the flanking fingers as the bottom-most stud is transferred from the central finger to the other flanking finger, and a spring located in each of the outer cavities to return the respective fingers to their normal positions, the correlated spring conjointly returning the centrally positioned finger to its normal position wherein the stack is again restrained by the centrally positioned finger as the other flanking finger releases the bottom-most stud.

3. A pneumatically operated escapement for feeding one stud at a time from a magazine, comprising a body having a passageway therein forming a path along which the studs proceed in stacked relationship from the magazine, said body also having three cylindrical cavities therein whose respective axes intersect the axis of the passageway, three plungers each having a correlated finger associated therewith reciprocatingly disposed in the respective cavities, a spring biasing the centrally positioned finger to a normal position wherein it blocks the passageway thereby to restrain the stack of studs, the two outer cavities being located to position the two flanking fingers along the passageway on either side of the central finger at respective distances greater than the longitudinal length of one of the studs,

springs biasing the two flanking fingers respectively so that they are normally held clear of the passageway, and means for connecting said central cavity with an air supply to retract the centrally positioned finger to release the stack, said means subsequently moving the flanking fingers into their blocking positions wherein the stack is restrained by one of the flanking fingers as the bottom-most stud is transferred from the central finger to the other flanking finger, the disconnecting of the air supply permitting the springs to return the fingers to their normal positions wherein the stack is again restrained by the centrally positioned finger as the flanking finger releases the bottom-most stud.

. HAROLD J. GRAHAM.

PAUL F. POWDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,250,741 Wickham Dec. 18, 1917 1,332,538 Bourque Mar. 2, 1920 1,845,651 Dickson Feb. 16, 1932 

